Method of imparting directional permanency of folding to sheet, and apparatus therefor

ABSTRACT

A method of imparting directional permanency of folding to a sheet, and an apparatus therefor, which is suitable for manufacturing frame bodies, cushioning members and other block products for packaging, from a sheet of paper and other recyclable materials. The method includes a step of moving respective folding working tools, disposed on one or both surfaces of a sheet, required amounts so as to fold the sheet along respective folding ruled lines, and a step of shortening spacings between the respective folding working tools in a uniform ratio in accordance with an apparent amount of shortening in a longitudinal dimension caused by the shifting, while synchronizing with the moving step. Directional permanency of folding can be accurately imparted to the sheet along the folding ruled lines.

FIELD OF THE INVENTION

This invention relates to a method of imparting directional permanencyof folding to a sheet efficiently, when one or a plurality of ridge-like(outward) folds and one or a plurality of valley-like (inward) folds areformed alternately in a sheet such as a pasteboard, a corrugatedcardboard or other sheets having some degree of hardness, along foldingruled lines formed in parallel and orthogonal to the longitudinaldimension of the sheet, so that the sheet is folded accurately inaccordance with the design in the following processing. This inventionalso relates to an apparatus for the method.

BACKGROUND OF THE INVENTION

Recently, it has been proposed to use, as frame bodies for protectingand packaging an electric or electronic equipment product effectivelywhen the articles are packed in a case or cushioning members forpackaging, a recyclable sheet such as a pasteboard or a corrugatedcardboard instead of a plastic foam body such as styrene foam.

One frame body or cushioning member is a corrugated cardboard blockformed by zigzag folding of the sheet.

Another frame body or cushioning member using corrugated cardboard orthe pasteboard is, for example, as disclosed in Japanese Utility ModelApplication laid-open No.60-32274, a hollow block with apseudo-honeycomb section formed by repeatedly folding a sheet at apredetermined interval and bonding or connecting necessary folds (foldedparts) to each other.

In manufacturing the above-mentioned frame bodies or cushioning members,at first, the sheet member such as the pasteboard or the corrugatedcardboard is cut according to the design and folding ruled lines areformed orthogonal to the longitudinal dimension of the sheet with presslines by a press, perforated lines, intermittent cutting lines or thelike according to the design.

Next, the sheet is folded along the above-mentioned ruled lines so thatthe ridge-like folds and the valley-like folds are formed alternatelyand then necessary portions are pasted to each other to make a block ofa desired shape.

The frame bodies or cushioning members should be manufactured to have anaccurate shape and size, since, as previously mentioned, they are usedfor supporting articles properly and protecting the articles from impactin circulation and for packaging the articles easily and efficiently.

It is difficult to manufacture the product of an accurate shape and sizebecause the folded part tends to shift easily when the sheet, formed asabove-mentioned, is folded by industrial means along the folding ruledlines. In order to fold the sheet along the folding ruled linesaccurately and industrially, it is preferable to give directionalpermanency of folding (folding habit) to the folding ruled lines of thesheet.

However, no industrial means for imparting accurate directionalpermanency of folding to the sheet along many folding ruled lines formedin the sheet has been developed (it has been conducted by handwork).Therefore, the frame bodies or cushioning members of plastic foam havenot been yet replaced by those using the sheet of a pasteboard, acorrugated cardboard or other recyclable materials.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a method of impartingdirectional permanency of folding to a sheet accurately and quicklyalong many folding ruled lines formed in the sheet beforehand, in themanufacturing process of the frame bodies, cushioning members or otherblock products made of paper or other easily recyclable materials.

Another object of the present invention is to provide an apparatus forsuitably performing the method of imparting directional permanency offolding to a sheet to achieve the abovementioned object.

Another object of the present invention is to provide an apparatus forimparting directional permanency of folding to a sheet, which is capableof forming two different kinds of ridge-like folds (a reverse V-shapedfold and a reverse U-shaped fold) and two different kinds of valley-likefolds (a V-shaped fold and a U-shaped fold) in the same apparatus.

Another object of the present invention is to provide an apparatus forimparting directional permanency of folding to a sheet, which is capableof imparting directional permanency of folding, to various kinds ofsheet in the same apparatus, even though the distances between foldingruled lines formed in a large number in the sheet vary depending on thekind of sheet to be processed.

In order to achieve the above-mentioned objects, the method of impartingdirectional permanency of folding to a sheet according to the presentinvention is as follows.

A method of imparting directional permanency of folding to a sheetaccording to the first embodiment of the method of the present inventioncomprises, in a process for forming ridge-like folds a6 and valley-likefolds a7 alternately in a sheet a, a first step of supplying the sheet aformed with many folding ruled lines a2 in parallel and orthogonal tothe longitudinal dimension of the sheet, to a predetermined workingposition lb, a second step of disposing respective folding working tools21-26 along the respective folding ruled lines a2 on the surface of thesheet which becomes an inner surface when the sheet a is folded alongthe respective folding ruled lines a2, a third step of shiftingrespective folding working tools 21-26, 31-36, disposed on one or bothsurfaces of the sheet a, in required amounts in the folding directionalong respective folding ruled lines 2 a and a fourth step of shorteningdistances between the respective folding working tools 21-26, 31-36 at auniform ratio in accordance with an apparent amount of shortening of thelongitudinal dimension caused by the shifting, while synchronizing withthe third step.

According to the method of imparting folding directional permanency to asheet of the first embodiment, since the method comprises the third stepof shifting respective folding working tools 21-26, 31-36, disposed onone or both surfaces of the sheet a, in required amounts so that thesheet a is bent along the respective folding ruled lines a2 and thefourth step of shortening distances between the respective foldingworking tools 21-26, 31-36 at a uniform ratio in accordance with anapparent amount of shortening of the longitudinal dimension caused bythe shifting while synchronizing with the third step, the foldingdirectional permanency can be imparted to the sheet a along the foldingruled lines a2 accurately and industrially.

Therefore, it enables the product to be manufactured in an accuratesolid shape from the sheet a industrially.

A method of imparting directional permanency of folding to a sheetaccording to a second embodiment of the present invention comprises, inaddition to the steps of imparting directional permanency of folding toa sheet according to the first embodiment, a fifth step of moving therespective folding working tools 21-26, 31-36 away from the sheet aafter the fourth step and a sixth step of returning the respectivefolding working tools 21-26, 31-36 to the initial position, and thefirst step to the sixth step are repeated.

According to the method of imparting folding directional permanency to asheet in the second embodiment, since the method comprises the fifthstep of moving the respective folding working tools 21-26, 31-36 awayfrom the sheet a and the sixth step of returning the respective foldingworking tools 21-26, 31-36 to the original position and a cycle from thefirst step to the sixth step is repeated, directional permanency offolding can be imparted to a long sheet continuously and accurately.

A method of imparting directional permanency of folding to a sheetaccording to a third embodiment of the present invention is amodification of the process of imparting directional permanency offolding to a sheet according to the first embodiment, wherein the sheeta is supplied to a predetermined working position lb in the second stepby conveying it from one side to the other side along its longitudinaldirection, the folding working tool located at the beginning or the endof the working position, in the conveyance direction of the sheet a inthe second step, is defined as a reference, and the other working toolsare moved toward the reference working tool in the fourth step.

According to the method of imparting directional permanency of foldingto a sheet of the third embodiment, since the sheet a is supplied to theworking position lb by conveying it from one side to the other side in apath extending along its longitudinal dimension in the second step, thedirectional permanency of folding can be applied to a long sheet moresmoothly.

A method of imparting directional permanency of folding to a sheetaccording to a fourth embodiment of the present invention involves amodification of the fourth step of the third embodiment, wherein thereference working tool is moved in the same or opposite direction ofmovement of the sheet a in the second step.

According to the method of imparting directional permanency of foldingto a sheet of the fourth embodiment, since the folding working toollocated at the beginning of the working position, in the movingdirection of the sheet a by the conveying means, is defined as areference and the reference working tool is moved along the movingdirection of the sheet a in the second step, together with the otherworking tools, in the fourth step, directional permanency of folding canbe applied more smoothly to the long sheet continuously.

A method of imparting directional permanency of folding to a sheetaccording to a fifth embodiment of the present invention comprises, in aprocess for forming ridge-like folds a6 and valley-like folds a7alternately in a sheet, a first step of supplying the sheet a formedwith many pairs of parallel folding ruled lines a2 in parallel andorthogonal to the longitudinal dimension of the sheet, to apredetermined working position lb, a second step of disposing pairs ofthe folding working tools 21•31-26•36 along the pairs of the respectivefolding ruled lines a2 on the surface of the sheet which becomes aninner surface when the sheet a is folded along the respective foldingruled lines a2, a third step of shifting respective pairs of the foldingworking tools 21•31-26•36, disposed on one or both surfaces of the sheeta, in required amounts in the folding direction along the respectivepairs of the folding ruled lines a2 and a fourth step of shorteningdistances between the respective pairs of the folding working tools21•31-26•36 at a uniform ratio in accordance with an apparent amount ofshortening of the longitudinal dimension caused by the shifting whilesynchronizing with the third step.

According to the method of imparting folding directional permanency offolding to a sheet of the 5th embodiment, since the method comprises thethird step of shifting respective pairs of the folding working tools21•31-26•36, disposed on one or both surfaces of the sheet a, inrequired amounts so that the sheet a is bent along the respective pairsof the folding ruled lines a2 and the fourth step of shorteningdistances between the respective folding working tools 21•31-26•36 at auniform ratio in accordance with an apparent amount of shortening of thelongitudinal dimension caused by the shifting while synchronizing withthe third step, the directional permanency of folding can be imparted tothe sheet a along the pairs of the folding ruled lines a2 accurately andindustrially to produce a hollow block from the sheet.

A method of imparting directional permanency of folding to a sheetaccording to a sixth embodiment of the present invention comprises, inaddition to the steps of the method of the fifth embodiment, a fifthstep of moving the respective pairs of the folding working tools21•31-26•36 away from the sheet a after the fourth step and a sixth stepof returning the respective pairs of the folding working tools21•31-26•36 to the initial position, and the first to the sixth stepsare repeated.

According to the method of imparting directional permanency of foldingto a sheet in the sixth embodiment, since the method comprises the fifthstep of moving the respective pairs of the folding working tools21•31-26•36 away from the sheet a and the sixth step of returning therespective pairs of the folding working tools 21•31-26•36 to theoriginal position and a cycle from the first step to the sixth step isrepeated, directional permanency of folding can be imparted to a longsheet along the pairs of the ruled lines a2 continuously and accurately.

A method of imparting directional permanency of folding to a sheetaccording to the seventh embodiment of the present invention is amodification of the fifth embodiment wherein the sheet a is supplied tothe predetermined working position lb in the second step by transportingit from one side to the other side in a path extending along itslongitudinal dimension.

According to the method of imparting directional permanency of foldingto a sheet of the seventh embodiment, since the sheet a is supplied bytransporting it from one side to the other side in a path extendingalong its longitudinal dimension, the directional permanency of foldingcan be applied to the sheet along the pairs of the folding ruled linesa2 more smoothly.

A method of imparting directional permanency of folding to a sheetaccording to an eighth embodiment of the present invention involves amodification of the fourth step of the method according to the seventhembodiment, wherein the distances between the respective pairs of theworking tools are shortened while they are moved along the conveyancedirection of the sheet in the second step.

According to the eighth embodiment, since the respective pairs of theworking tools 21•31-26•36 are moved along the conveyance path of thesheet a, the directional permanency of folding can be more smoothlyapplied to a long sheet continuously.

A method of imparting directional permanency of folding to a sheet of a9th embodiment of the present invention is a modification of the fifthembodiment wherein the folding working tools of the pair are constitutedseparately, and are moved synchronously by respective driving means inthe fourth step.

In the method of the 9th embodiment, since the folding working tools ofthe pair are constituted separately, and are moved synchronously byrespective driving means in the fourth step, the distances between thefolding working tools of the pair can be adjusted.

The method of the 10th embodiment of the present invention is also amodification of the fifth embodiment, wherein the folding working toolsof the pair are constituted unitarily and are moved by a single drivingmeans in the fourth step.

In the method of the 10th embodiment, since the folding working tools ofthe pair are constituted unitarily and are moved by the same drivingmeans in the fourth step, control becomes unnecessary to keep thedistance between the folding working tools of the pair constant or theamount of the control becomes small.

A method of imparting directional permanency of folding to a sheetaccording to 11th embodiment of the present invention is a modificationof the first or the fifth embodiment wherein the sheet a is a corrugatedcardboard, at least some of the ruled lines a2 are intermittent cuttinglines formed by cutting the sheet a intermittently across thecorrugations al of the corrugated cardboard or are each composed of acut portion a3 of a predetermined length formed on the sheet a bycutting, a non-cut portion a4 of a shorter length than the cut portion,the cuts and uncut portions being located alternately so as to intersectthe corrugations al of the corrugated cardboard, and an additional cutportion a5 of a shorter length located at the end of each cut portion a3and inclined toward the non-cut portion a4 adjacent the associated cutportion a3.

According to the method of the eleventh embodiment, in case that thesheet a is a corrugated cardboard, directional permanency of folding canbe imparted to the sheet a without causing breaking of the sheet a atthe folds when it is folded along the folding ruled lines a2.

A method of imparting directional permanency of folding to a sheetaccording to a 12th embodiment of the present invention is an adaptionof the first or the fifth embodiment to a pasteboard sheet, wherein atleast some of the ruled lines a2 are pressed lines formed on the sheet aby a press or intermittent cutting lines formed on the sheet a bycutting.

The method of imparting directional permanency of folding to a sheetaccording to the 12th embodiment makes the formation of the foldingruled lines a2 easier, when the sheet a is pasteboard.

In order to attain the aforementioned objects of the present invention,an apparatus for imparting directional permanency of folding to a sheetaccording to the present invention is as follows.

An apparatus for imparting directional permanency of folding to a sheetaccording to the 13th embodiment of the present invention comprises:

a plurality of folding working tools which are located at predeterminedintervals so as to face the sheet a, located at a working position,alternately from opposing sides of sheet, and have distal ends directedtoward the sheet a along folding ruled lines a2 formed on the sheetorthogonal to its longitudinal dimension,

folding drive means for moving a first plurality of the working tools,e.g. lower working tools, perpendicular to one side of the sheet a untilthe sheet a is bent to some extent along the respective folding ruledlines and then returns the working tools to their initial positions,

shuttle drive means for moving one plurality of folding working toolsfrom one side of the working position, in the direction of sheetconveyance, toward an opposite side of the working position, so as toshorten the distances between the respective folding working tools21-26,31-36 at a uniform ratio and returns the working tools to the oneside, and

advancing drive means for moving a second plurality of the respectivefolding working tools away from or back to a position facing a secondsheet surface.

The method of the present invention can be performed smoothly and surelyby this apparatus for imparting directional permanency of folding to asheet, because, when the sheet a is folded by the folding drive means 4,the respective folding working tools 21-26,31-36 are moved from theirinitial positions toward one side edge of the sheet a by the shuttledrive means 5.5 a, 6.6 so that the distances between them are shortenedin a uniform ratio from the original distances.

Further, since the apparatus is provided with the advancing drive means7 a, 7 which move the respective folding working tools 21-26,31-36 awayfrom or toward the working position at the sheet surface, the sheet acan be handled easily after folded and a control cycle of impartingdirectional permanency of folding to the sheet can be repeated.

An apparatus for imparting directional permanency of folding to a sheetaccording to the 14th embodiment of the present invention comprises, inaddition to the apparatus components of the 13th embodiment, shiftingmeans for shifting a second plurality of the folding working tools21-26,31-36 so as to shorten or lengthen the distance between adjacentworking tools.

Since the apparatus for imparting directional permanency of folding to asheet according to the 14th embodiment comprises shifting means 80•81,9which shifts a second plurality of the folding working tools 21-26,31-36so as to shorten or lengthen the distance between adjacent workingtools, the distances between the folding working tools 21-26,31-36 canbe adjusted and the method of the present invention can be performed inthe same apparatus by controlling the moving velocity of the foldingworking tools by the shuttle driving means 5•5 a, 6•6 a.

According to the apparatus for imparting directional permanency offolding to a sheet of the 15th embodiment of the present invention, theabove-mentioned shifting means 80•81, 9 of the apparatus of the 14thembodiment is provided with screw shafts 80 h•81 h, 9 b, the rotation ofwhich is properly controlled by motors 80 g•81 g, 9 a and screw guides80 i, 9 c through which the screw shafts 80 h•81 h, 9 b extend.

In the apparatus for imparting directional permanency of folding to asheet according to the 15th embodiment, since the above-mentioned shiftmeans 80.81 and 9 comprises screw shafts 80 h•81 h, 9 b whose rotationis controlled by motors 80 g•81 g, 9 a and screw guides 80 i, 9 cthrough which the screw shafts 80 h•81 h, 9 b extend, the movingvelocity of the folding working tools moved by the shuttle drive means5.5 a, 6.6 a can be controlled very easily and the control can be donemore accurately.

An apparatus for imparting directional permanency of folding to a sheetaccording to the 16th embodiment of the present invention furthercomprises, in addition to the apparatus components of the 13thembodiment, actuators 21 a-26 a for all or some of the folding workingtools 21-26,31-36 for moving the corresponding folding working tools21-26,31-36 toward or away from the sheet a independently.

Since the apparatus for imparting directional permanency of folding to asheet of the 16th embodiment is provided with actuators 21 a-26 a forall or some of the folding working tools 21-26,31-36, for moving thecorresponding folding working tools 21-26,31-36 toward or away from thesheet a independently, if some working tool(s) is not required forimparting directional permanency of folding to the sheet a, that workingtool(s) alone can be retracted.

An apparatus for imparting directional permanency of folding to a sheetaccording to the 17th embodiment of the present invention furthercomprises, in addition to the apparatus components of the 13thembodiment, conveying means which supplies the sheet a to the workingposition 1 b by transporting it in a direction parallel to its lengthand the shuttle drive means 5•5 a, 6•6 move the respective foldingworking tools 21-26,31-36 in the direction of conveyance by theconveying means so as to shorten the initial distances between therespective folding working tools 21-26,31-36 in a uniform ratio.

The apparatus of the 17th embodiment is very useful for repeating acycle consisting of conveyance of the sheet and imparting directionalpermanency of folding to the sheet, since it is provided with theconveying means which supplies the sheet a to the working position 1 bby transporting it in its longitudinal direction and the shuttle drivemeans 5•5 a, 6•6 thereof move the respective folding working tools21-26, 31-36 in the direction of conveyance by the conveying means so asto shorten the initial distances between the respective folding workingtools 21-26,31-36 in a uniform ratio.

An apparatus for imparting directional permanency of folding to a sheetaccording to the 13th embodiment of the present invention furthercomprises, in addition to the apparatus of the 13th embodiment, sheetguides 1 h having many guide bars 1 i in parallel along the longitudinaldimension of the sheet a at the working position 1 b of the sheet a and,corresponding to the guide bars 1 i, many indentations (cut outs) formedat the tips of the respective folding working tools 21-26, 31-36 drivenby the folding drive means.

In the apparatus for imparting directional permanency of folding to asheet of the 18th embodiment, the sheet can be supplied to the workingposition in a stable state and imparting of directional permanency tothe sheet a is performed more smoothly, because of the sheet guides 1 hand the indentations (cut outs) formed in the tips of the respectivefolding working tools 21-26,31-36 driven by the folding drive means.

An apparatus for imparting directional permanency of folding to a sheetaccording to a 19th embodiment of the present invention is anarrangement of the 13th embodiment wherein the sheet a is supplied tothe working position 1 b horizontally and folding working tools 21-26facing one side of the sheet a are located so as to face the sheet fromthe under side and folding working tools 31-36 are located so as to facethe sheet from the upper side.

In the apparatus for imparting directional permanency of folding to asheet according to the 19th embodiment, the operation of the respectivefolding working tools 21-26, 31-36 can be easily controlled and therespective folding working tools 21-26, 31-36 can be operated easily,because the sheet a is supplied to the working position 1 b horizontallyand folding working tools 21-26 are located below the sheet and foldingworking tools 31-36 are located above the sheet.

The 20th embodiment of the present invention is a modification of theapparatus of the 13th embodiment wherein each of the shuttle drivingmeans 5•5 a, 6•6 a comprises at least one pair of sprockets 51 a•51 b-56a•56 b, 61 a•61 b-66 a•66 b corresponding to the respective foldingworking tools 21-26,31-36, endless timing belts or chains 51-56, 61-66mounted on the pairs of sprockets 51 a•51 b-56 a•56 b, 61 a•61 b-66 a•66b and supporting the corresponding folding working tools 21-26,31-36,and pairs of guide rails 51 d-56 d, 61 d-66 d which guide the respectivefolding working tools 21-26, 31-36 when they are moved, and at least,the pairs of sprockets 51 a•51 b-56 a•56 b corresponding to therespective folding working tools 21-26 facing one side of the sheet aand the pairs of sprockets 61 a•61 b-66 a•66 b corresponding to therespective folding working tools 31-36 facing the other side of thesheet a, are driven separately by different motors 5 b•5 c•6 b•6 c,respectively, to make the circumferential velocities of the timing beltsor chains 51-56, 61-66 different.

According to an apparatus for imparting directional permanency offolding to a sheet of the 20th embodiment, movement of the respectivefolding working tools 21-26, 31-36 can be controlled very easily toshorten the initial distances between them in a uniform ratio, becausethe shuttle drive means 5•5 a, 6•6 a are provided with one pair ofsprockets 51 a•51 b-56 a•56 b, 61 a•61 b-66 a•66 b corresponding to therespective folding working tools 21-26, 31-36, endless timing belts orchains 51-56, 61-66 mounted on the pairs of sprockets 51 a•51 b•56 a•56b, 61 a•61 b-66 a•66 b and supporting the corresponding folding workingtools 21-26,31-36, and the circumferential velocity of each of thetiming belts or chains 51-56, 61-66 is different.

In addition, since the apparatus is provided with pairs of guide rails51 d-56 d, 61 d-66 d which guide the respective folding working tools21-26, 31-36 when they are moved, the respective folding working tools21-26, 31-36 can be moved in a stable state.

Therefore, directional permanency of folding can be added to the sheet amore smoothly, accurately and on an industrial scale.

The apparatus for imparting directional permanency of folding to a sheetof the 21st embodiment of the present invention is a modification of the13th embodiment wherein all or some of the folding working tools 21-26and 31-36 have their tips thereof lying along the adjacent folding ruledlines a2 in the sheet a.

The moving velocities of some of working tools need not be correctedwhen directional permanency of folding is imparted to the sheet a alongthe pairs of the folding ruled lines a2, because the tips of all or someof the folding working tools 21-26 and 31-36 lie along the adjacentfolding ruled lines a2 in the sheet a.

The apparatus for imparting directional permanency of folding to a sheetof the 22nd embodiment of the present invention is a modification of theapparatus of the 13th embodiment wherein main parts 24 b, 32 b of thefolding working tools 21-26 and 31-36, except for at least base parts 24c, 32 a thereof, are exchangeably connected to the base parts 24 c, 32a.

In the apparatus of the 22nd embodiment, the main parts 24 b, 32 b canbe easily exchanged because they are exchangeably connected to the baseparts 24 c, 32 a.

The apparatus for imparting directional permanency of folding to a sheetof the 23rd embodiment of the present invention is a modification of the22nd embodiment wherein main parts 24 b, 32 b of the folding workingtools 21-26 and 31-36, except for the base parts 24 c, 32 a, arecomposed of plates.

The apparatus of 23rd embodiment is most suitable for impartingdirectional permanency of folding to a sheet, since the main parts 24 b,32 b of the folding working tools 21-26 and 31-36 are composed ofplates.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a schematic side view of the essential parts of the apparatusfor imparting directional permanency of folding according to the 1stembodiment of the present invention.

FIG. 2 is a side view of the apparatus of the 1st embodiment, where apart thereof is omitted.

FIG. 3 is an enlarged cross sectional view of the main parts along thearrow A—A of FIG. 2.

FIG. 4 is a partial side view of a lower part of the apparatus of FIG.2, the level of which is lower than the working position.

FIG. 5 is a schematic plan view of a shifting mechanism and shuttledrive means in the lower part of the apparatus of FIG. 4.

FIG. 6 is an enlarged cross-sectional view of the main parts taken alongthe arrow B—B of FIG. 4.

FIG. 7 is a schematic side view of an upper part of the apparatus of the1st embodiment, the level of which is higher than the working position.

FIG. 8 is a schematic plan view of a shifting mechanism and shuttledrive means in the upper part of the apparatus of the 1st embodiment.

FIG. 9 is an enlarged cross-sectional view of the main parts along thearrow C—C of FIG. 7.

FIG. 10 is an enlarged side view of the lower folding working tool.

FIG. 11 is an enlarged side view of the upper folding working tool.

FIG. 12 is a plan view of a part of the sheet used for the method ofimparting directional permanency of folding according to the firstembodiment of the present invention.

FIG. 13 is a plan view of a part of the sheet used for the method ofimparting directional permanency of folding according to the thirdembodiment of the present invention.

FIGS. 14a-14 c are schematic views showing the relationship of the sheetand the respective folding working tools in the method of the firstembodiment of the present invention, where FIG. 14a is a partial sideview showing the state that the respective folding working tools are setto the working position after the sheet is supplied there, FIG. 14b is apartial side view showing the state wherein directional permanency offolding is being imparted to the sheet and FIG. 14c is a partial sideview showing the state wherein directional permanency of folding hasbeen imparted to the sheet.

FIG. 15 is a side view of the sheet having directional permanency offolding imparted according to the 1st embodiment of the presentinvention.

FIG. 16 is a partial side view of another version of the 15t embodimentof the present invention, showing the relationship between therespective folding working tools and the sheet in the state whereindirectional permanency is being imparted.

FIG. 17 is a partial side view showing the state wherein directionalpermanency of folding has been imparted to the sheet.

FIG. 18 is a plan view of a part of the sheet used in the method of the2nd embodiment of the present invention.

FIG. 19 is a schematic side view showing the state wherein directionalpermanency has been imparted to the sheet shown in FIG. 18.

FIG. 20 is a partial side view showing the state wherein the respectivefolding working tools are set to the working position after the sheet issupplied there in the method of the 3rd embodiment of the presentinvention.

FIG. 21 is a partial side view showing the state wherein working processhas proceeded from that shown in FIG. 20 and directional permanency offolding is imparted to the sheet to some extent.

FIG. 22 is a partial side view showing the state wherein the workingprocess has further proceeded from the state of FIG. 21 and directionalpermanency of folding is imparted to the sheet.

FIG. 23 is a schematic side view of a block manufactured from the sheethaving directional permanency of folding imparted by the method of the3rd embodiment.

FIG. 24 is a plan view of a part of the sheet used in the method of the4th embodiment of folding according to the present invention.

FIGS. 25a-25 c are explanatory views of a method of the 4th embodimentof the present invention, wherein FIG. 25a is a partial side viewshowing the state where the respective folding working tools are set tothe working position after the sheet is supplied there, FIG. 25b is apartial side view showing the state wherein directional permanency isbeing imparted to the sheet and FIG. 25c is a side view of a part of ablock manufactured from the sheet having directional permanency offolding imparted.

FIGS 26 a-26 d are partial side views of folding working tools ofdifferent shapes which may be utilized in the second embodiment of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An apparatus for imparting directional permanency of folding to a sheetaccording to the first embodiment of the present invention will beexplained hereinafter with the reference of FIGS. 1-11.

Referring now to FIG. 1, an outline of the apparatus of the firstembodiment will be explained.

In FIGS. 1, 1 a is a conveying means for supplying a sheet a almosthorizontally from the left side of the drawing to the right side.

Folding working tools consisting of plates 21, 22, 23, 24, 25, 26 and31, 32, 33, 34, 35, 36 are disposed above and under the working positionlb, respectively, so that they face the conveyed sheet a alternatelyfrom the under side and the upper side at a constant distance(interval).

The respective folding working tools 21-26 and 31-36 are parallel toeach other and their distal ends are approximately orthogonal to thelongitudinal dimension of the sheet a.

Beneath the working position 1 b, a folding drive means 4 is providedwhich moves the lower working tools 21-26 upwards or downwards through arequired distance to fold the sheet a, shuttle drive means 5, 5 a whichmove the working tools 21-26 rightwards or leftwards of the drawing at adifferent velocity and shifting means 80, 81 each of which moves theworking tools 21, 23, 25 or 22, 24, 26 rightwards or leftwards of thedrawing independently of the shuttle drive means 5.

Above the working position 1 b, an advancing drive means 7 is providedfor raising and lowering the upper working tools 31-36 to and from theposition represented by a solid line in FIG. 1. Shuttle drive means 6, 6a move the working tools 31-36 rightwards or leftwards of the drawing ata different velocity and shifting means 9 moves the working tools 31,33, 35 rightwards or leftwards of the drawing independently of theshuttle drive means 6.

Actuators 21 a, 22 a, 23 a, 24 a, 25 a, and 26 a, each consisting of anair cylinder, are connected to the lower working tools 21-26respectively in order to move them upwards or downwards through arequired distance. These actuators 21 a-26 a also function as advancingdrive means 7 a which moves the lower working tools 21-26 downwards fromthe position represented by a solid line to a retracted position andfrom the retracted position to an advanced position.

In FIG. 1, the lower advancing drive means 5 and 5 a and the upperadvancing drive means 6 and 6 a are shown in vertical arrangementrespectively for the convenience of explanation but, as explained later,they are actually disposed at the same level.

The apparatus of this embodiment will be explained in detail with thereference of FIGS. 1-11 hereafter.

The conveying means la is provided with a pair of pulleys with teeth(sprockets) 1 c, 1 d installed in the frame 1, extending along theconveyance direction, timing belts (or chains) 1 e mounted on thepulleys 1 c, 1 d under tension by a tension belt (not shown in thefigure) and a vacuum chuck 1 g connected to the respective timing belts1 e. The right hand pulley id is driven by a motor with a decelerator(not shown in the figure).

The vacuum chucks 1 g run along guide rails 1 f which are set inparallel to the respective timing belts 1 e as shown in FIGS. 1-3, undercontrol of control means (not shown in the figure).

As shown in FIGS. 2-4, a sheet guide 1 h, which consists of many guidebars 1 i disposed at a regular interval, is installed at the conveyancelevel (including working position lb) of the conveying means 1 a so thatthe guide extends along the conveyance path defined by conveying means 1a.

FIGS. 1-6 show a lower movable frame 50, both sides of which areconnected with the folding drive means, and which is moved up and downwith a fixed stroke by this folding drive means 4.

The folding drive means 4 consists of a motor 40 shown in FIG. 2, adecelerator 41 connected with the motor 40, a rotation transmittingshaft 42 shown in FIG. 3 which receives the rotation from thedecelerator 41, screw shafts 44 connected with the rotation transmittingshaft 42 through rotation conversion means 43, screw guides 45 fixed tothe frame 1 and so on. Therefore, the movable frame is moved upwards ordownwards by a regular or opposite rotation of the screw shafts 44 whichextend through the screw guides 45.

When the movable frame 50 is thus moved upwards or downwards, lowfriction bodies 46 (FIG. 2), which are connected to the frame 50 at fourpoints, are guided by elevator guides 47 fixed to the prop of the frame1 to stabilize the motion of the movable frame.

The lower shuttling drive means 5 and 5 a are installed on the movableframe 50 as shown in FIGS. 4-6.

As explained in detail hereinafter, one of the drive means 5 moves theworking tools 21, 23, 25 along the level of the working position 1 b andthe other drive means 5 a moves the working tools 22, 24, 26 along thelevel of the working position 1 b.

As shown in FIGS. 5 and 6, on the upper parts of both sides of themovable frame 50, one pair of guide rails 80 a, 80 b and guide rails 80c, 80 d and another pair of guide rails 81 a, 81 b and guide rails 81 c,81 d are disposed in parallel respectively along the conveyance pathdefined by the conveying means of FIG. 2.

A pair of movable stands 80 e, 80 f is disposed on the one pair of theguide rails 80 a, 80 b and guide rails 80 c, 80 d so as to run on alinear bearing 80 j (FIG. 6).

Another pair of movable stands 81 e, 81 f is disposed above the otherpair of the guide rails 81 a, 81 b and guide rails 81 c, 81 d so as torun on a linear bearing 81 j (FIG. 6).

Each pair of the movable stands 80 e, 80 f and the movable stands 81 e,81 f is connected with a connecting bar 82 (FIG. 4), respectively, sothat each pair moves in unison.

As shown in FIGS. 5 and 6, shafts 5 f, 5 g, which are rotated by themotors (servo-motors) 5 b, 5 c through the decelerators 5 d, 5 e,respectively, are supported by the respective members 5 h, 5 i and 5 j,5 k on the sides of the movable stands 80 e and 81 e.

Pulleys with teeth (sprockets) 51 a, 53 a, 55 a and pulleys with teeth(sprockets) 52 a, 54 a, and 56 a, each of which has a different diameter(increasing in this order) are installed on the rotary shafts 5 f, 5 g,respectively.

Corresponding to the above-mentioned pulleys 51 a, 53 a, 55 a, 52 a, 54a and 56 a, pulleys with teeth (sprockets) 51 b, 53 b, 55 b, 52 b, 54 b,and 56 b of the same diameter are installed on the other movable stands80 f and 81 f respectively.

Timing belts (or chains) 51, 52, 53, 54, 55, and 56 are run around thepulleys 51 a, 51 b, the pulleys 52 a, 52 b, the pulleys 53 a, 53 b, thepulleys 54 a, 54 b, the pulleys 55 a, 55 b and the pulleys 56 a, 56 brespectively through tension pulleys 57, 58, and 59.

The above-mentioned folding working tools 21, 23, 24, 25, and 26 areconnected respectively to the upper runs of the respective timing belts51, 52, 53, 54, 55, and 56 by connecting pieces 51 c, 52 c, 53 c, 54 c,55 c, and 56 c.

Guide rails 51 d, 52 d, 53 d, 54 d, 55 d, and 56 d are disposed on themovable frame 50 in parallel and close to the running part of therespective timing belts 51-56. The respective folding working tools21-26 are pulled by the respective timing belt 51-56, as the rotaryshafts 5 f, 5 g rotate regularly or in reverse, and run along the guiderails through two linear bearings 27.

In this embodiment, working tools 21 and 26 run along guide rails 51 dand 56 d, working tools 22 and 25 run along guide rails 52 d and 55 d,and working tools 23 and 24 run along guide rails 53 d and 54 drespectively.

The shifting means 80 is composed of the above-mentioned guide rails 80a, 80 b, 80 c, 80 d, the movable stands 80 e, 80 f connected with eachother, a motor 80 g with a deceleration function, a screw shaft 80 hrotated by the motor 80 g and the like.

As shown in FIG. 4, when the screw shaft 80 h is rotated regularly or inreverse by the motor 80, the screw guide 80 i threaded on the screwshaft 80 h moves rightwards or leftwards in the figure together with themovable stands 80 e, 80 f. Thereby, the folding working tools 21, 23 and25 can be shifted together with the shuttle drive means 5 in the leftand right direction of the figure over a desired distance, at a desiredvelocity and at a necessary time.

The other shifting means 81, which is composed of guide rails 81 a, 81b, 81 c, 81 d, the movable stands 81 e, 81 f connected each other, amotor 81 g with a deceleration function, a screw shaft 81 h connectedwith the motor 80 g and the like, can shift the folding working tools22, 24, and 26 in the right and left directions of the figure togetherwith the shuttle drive means 5 a over a desired distance, at a desiredvelocity and at a necessary time, similarly to the above-mentionedshifting means 80.

Except for their bases, the lower working tools 21-26 are composed ofplates.

As shown in FIG. 10, where an enlarged folding working tool 24 is shown,the main part 24 b composed of a plate is connected on the frame-likebase 24 c by a screw (not show in the figure) and the base 24 c is fixedto the housing of the linear bearing 27 by a screw. Actuator 24 aconsisting of an air cylinder is attached to the side of the base 24 c.The main part 24 b is raised along the guide 24 d by operation of theactuator 24 a to a position where the tip (distal end of 24 b) islocated just beneath the working position 1 b of FIG. 2.

Other folding working tools 21, 22, 23, 25, and 26 have approximatelythe same construction as the above-described working tool 24.

Each of the folding working tools 21-26 has cut-outs 20 at positionscorresponding to the guide bars 1 i so that the distal end thereof doesnot contact the guide bars 1 i constituting the sheet guide 1 h, whentools 21-26 are raised by the folding drive means 4 shown in FIG. 3.

The upper movable frame 60, as shown in FIGS. 2 and 3, is moved up anddown in a stable state by the advancing drive means 7 consisting of anair cylinder connected to the upper center, as four elevator bodies 70depending from the bottom of the upper frame 60 are guided respectivelyby the respective guide posts 71 fixed on the frame 1.

As shown in FIGS. 7-9, the upper shuttle drive means 6, 6 a are disposedon the movable frame 60 and, as explained in detail hereinafter, one ofthe drive means 6 shuttles the folding working tools 31, 33, 35 and theother of the drive means 6 a shuttles the folding working tools 32, 34,36.

Two pairs of guide rails 90, 91 and 92, 93 are provided in parallelrespectively along the conveyance direction of the conveying means 1 aof FIG. 2 on front side of the upper part of both sides of the movableframe 60.

Movable stands 94, 95 connected mutually by a connecting bar 97 aredisposed on the guide rails 90, 91 and 92, 93 so as to slide through alinear bearing 96 (FIG. 9) As shown in FIGS. 8 and 9, rotary shafts 6 f,which are rotated by the motors (servo-motors) 6 b through thedecelerators 6 d, are supported by the respective bearing members 6 h, 6i on one of the movable stands 94.

A rotary shaft 6 g rotated by the motors (servo-motors) 6 c through thedecelerators 6 e is supported by the respective members 6 i, 6 k on theabove-mentioned movable stand 94 on the upper part of the movable frame60.

Pulleys with teeth (sprockets) 61 a, 63 a, 65 a of different diameters(increasing in order), and pulleys with teeth (sprockets) 62 a, 62 a and66 a of different diameters (increasing in order) are installed on therotary shafts 6 f, 6 g, respectively, on movable stand 94.

Corresponding to the above-mentioned pulleys 61 a, 63 a, 65 a andpulleys with teeth (sprockets) 61 b, 63 b, 65 b of the same diameter arerespectively installed on the other movable stand 95. Above the upperpart of the frame 30, close to the movable stand 95, pulleys with teeth(sprockets) 62 b, 64 b, and 66 b of the same diameter are respectivelyinstalled corresponding to the pulleys with teeth 62 a, 64 a and 66 a.

Timing belts (or chains) 61, 62, 63, 64, 65, and 66 are respectivelymounted on the pulleys with teeth 61 a, 61 b, the pulleys with teeth 62a, 62 b, the pulleys with teeth 63 a, 63 b, the pulleys with teeth 64 a,64 b, the pulleys with teeth 65 a, 65 b and the pulleys with teeth 66 a,66 b through respective tension pulleys 67, 68, and 69.

The above-mentioned folding working tools 31, 33, 34, 35 and 36 areconnected respectively to the lower runs of the respective timing belts61, 62, 63, 64, 65 and 66 with connecting pieces 61 c, 62 c, 63 c, 64 c,65 c and 66 c.

As shown FIGS. 3-8, guide rails 61 d, 62 d, 63 d, 64 d, 65 d and 66 dare disposed on the movable frame 60 in parallel and close to therespective timing belts 61-66. The respective folding working tools31-36 are moved by the respective timing belt 61-66, as the rotationshafts 6 f, 6 g rotate regularly or in reverse, and run along theassociated guide rails on linear bearings 37.

In this embodiment, folding working tools 31 and 36 run along guiderails 61 d and 66 d, working tools 32 and 35 run along guide rails 61 dand 66 d, and working tools 33 and 34 run along guide rails 63 d and 64d, respectively.

In this embodiment, the lower shuttle drive means 5, 5 a and the uppershuttle drive mean 6, 6 a operate synchronously and diameters of therespective pulleys 51 a-56 a and 61 a-66 a increase in the order of 51a, 61 a, 52 a, 62 a, 53 a, 63 a, 54 a, 64 a, 55 a, 65 a, 56 a, 66 a.

Accordingly, as for the velocity of movement in the horizontal directionof the respective working tools 21-26 and 31-36, the velocity of theworking tool 21 positioned on the right end of FIG. 2 is the smallestand that of the working tool 36 positioned on the left end of FIG. 2 isthe largest. In addition, the speed of movement in the horizontaldirection of the working tool 36 on the left end is set to be same asthe conveyance speed of the conveying means 1 a.

The shifting means 90 is composed of the above-mentioned guide rails 90,91, 92, 93, the movable stands 94, 95 connected to each other, a motor(servo-motor) 9 a with a deceleration function, a screw shaft 9 brotated by the motor 9 a and the like.

As shown in FIGS. 7 and 8, when the screw shaft 9 b is rotated regularlyor in reverse by the motor 9 a, the screw guide 9 c, through which thescrew shaft 9 c penetrates, moves rightwards or leftwards in FIGS. 7 and8 thereby driving the movable stands 94, 95. The folding working tools31, 33 and 35 are thereby shifted together with the shuttle drive means6 in the left and right direction of the figures through a desireddistance, at a desired velocity and at a necessary time.

The main portions of the respective upper folding working tools 31-36,except for the bases, are plates, similar to the lower folding workingtools 21-26.

FIG. 11 shows an enlarged view of the folding working tool 32. The mainpart 32 b consisting of the plate is connected to the tip of theframe-like base part 32 a by screws and the base part 32 a is fixed tothe housing of linear bearing 37 by screws. The other folding workingtools 31, 33-36 are similar to the working tool 32.

These folding working tools 31-36 are moved up and down from a positionrepresented by a solid line of FIG. 2 and FIG. 3 to a predeterminedlevel by the above-mentioned advancing drive means 7.

1st Embodiment of the Method for Imparting Directional Permanency ofFolding to a Sheet

The first embodiment of the method of imparting directional permanencyof folding to a sheet according to this invention will be explained interms of operation of the respective components of the apparatus of the1st embodiment with reference to FIGS. 1, 12 and 14-17.

The sheet a used in this embodiment is a B type corrugated cardboardformed with many ruled lines a2 in parallel with a spacing W of 150 mmand oriented approximately orthogonal to the corrugation al as shown inFIG. 12.

Each of the folding ruled lines a2 is composed of a cut portion a3 of apredetermined length formed on the sheet by cutting and a non-cutportion a4 of a shorter length than the cut portions a3. The cut andnon-cut portions alternate and are oriented so as to intersect thecorrugations al. An additional cut portion a5 of a shorter length isformed at the end of each cut portion a3 inclined toward the non-cutportion a4 adjacent to the cut portion a3.

The additional cut portion a5 serves to prevent the original corrugatedcardboard sheet a from tearing at the end of the cut portion a3 in thedirection across the cut portion a3 when the sheet a is folded along thefolding ruled line a2.

Although the additional cut portion a5 is formed on only one side of theend of the cut portion a3 in this embodiment, when the sheet a is athicker sheet such as an A type corrugated cardboard, the additional cutportion a5 is preferably formed extending in both longitudinaldirections from each end of the cut portion a3 and forms an arrow shapeat the ends of the cut portion a3, rather than a one-sided arrow.

Although the folding ruled lines have the non-cut portions a4 located atthe side edges of the sheet a in this embodiment, the folding ruledlines a2 may be formed so that cut portions are located on the sideedges of the sheet a depending on the application for which the productformed from the sheet a is intended.

By the operation of the shuttle drive means 5, 5 a, 6, 6 a, thedistances between the respective folding working tools 21-26 and thedistances between the respective folding working tools 31-36 areadjusted to be 300 mm, respectively, or the distances between the lowerfolding working tools 21-26 and the upper folding working tools 31-36are adjusted to be 150 mm, respectively.

In addition, the lower shuttle drive means 5, 5 a and the upper shuttledrive means 6, 6 a are adjusted so that, when the moving velocity of thebeginning (leading) folding working tool 21 is 175 to the right in thedrawing, the moving velocities of the other lower folding working tools22-26 become 225, 275, 325, 375, 425, respectively, and the movingvelocities of the upper folding working tools 31-36 become 200, 250,300, 350, 400, 450 respectively.

Before starting of working process, the respective lower working tools21-26 are located at retracted positions lower than the positionrepresented by a solid line of FIG. 1 and the respective upper workingtools 31-36 are located at retracted positions higher than the positionrepresented by a solid line of the drawing.

The sheet a is supplied to the working position 1 b by the conveyingmeans 1 a with each folding ruled line a2 being orthogonal to thedirection of conveyance by the conveying means 1 a.

After the sheet a is supplied to the working position lb, the upperadvancing drive means 7 and the actuators 21 a-26 a consisting the loweradvancing drive mean 7 a are operated so that the respective workingtools 31-36 and 21-16 are set at a level in the vicinity of or incontact with the sheet a as shown in FIG. 14.

In this state, the tip of the leading working tool 21 is controlled forlocation along the leading end of the sheet a and the tips of the otherworking tools 22-26 and 31-36 are controlled to be located along thefolding ruled lines a2, respectively.

Then, the lower folding working tools 21-26 are simultaneously andgradually raised by approximately 140 mm by the operation of the foldingdrive means 4 and at the same time the respective working tools 21-26and 31-36 are simultaneously moved rightward in FIG. 14 by the operationof the lower shuttle drive means 5, 5 a and the upper shuttle drivemeans 6, 6 a. At that time, the vacuum chuck 1 g of the conveying means1 a also moves in the same direction as the last working tool 36 and atthe same velocity.

Since the ratio of the moving velocities of the respective working tools21-26 and 31-36 is set as previously mentioned and the respectiveworking tools 21-26 and 31-36 are moved in the right direction toshorten the initial distances at a uniform ratio, the sheet a is folded,from a posture shown in FIGS. 14(a) to (c) through (b), so thatridge-like folds a6 and valley-like folds a7 are alternately formedalong the respective folding ruled lines a2.

After the sheet a is folded in a zigzag fashion as shown in FIG. (c) thevacuum chuck 1 g of the conveying means 1 a and the respective workingtools 21-26 and 31-36 stop moving.

Next, the respective working tools 21-26 are moved downward to theirrest position by the advancing drive means 7 a and the respectiveworking tools 31-36 are raised to their rest position by the advancingdrive means 7.

Afterwards, the thus folded sheet a is held between a pair of beltconveyers (not shown in the drawing) for example, and conveyed tosubsequent operations while fully extended flat. The respective workingtools 21-26 and 31-36 are returned to their initial positions by theshuttle drive means 5, 5 a and 6, 6 a.

When the length of sheet a is long, the sheet a is folded into the stateshown in FIG. 15 by repeating the cycle of the abovementioned operationof the apparatus of FIG. 1. In this case, the processed part of thesheet a, to which directional permanency of folding has already beenimparted, is preferably received by a pair of belt conveyers asdescribed above at every cycle of the operation of the apparatus of FIG.1.

The sheet a processed as mentioned above is conveyed to a pastingprocess in the extended (flat) state, where both sides of at least thefolded parts a6, a7 are pasted, and further conveyed to a foldingstation not shown in the drawing.

Employing a folding device after pasting the sheet a, in which theridge-like folds a6 and valley-like folds a7 are formed alternatelyalong the folding ruled lines a2 by the method of the above-mentionedembodiment, the sheet a is folded along the folds a6, a7 into a squareblock, accurately and according to the design.

Although the lower folding working tools 21-26 are raised (shifted) tothe limit in folding of the sheet a as shown in FIG. 14(d), it issufficient for them to be raised until the sheet a is bent along thefolding ruled lines a2 to some extent (at least 90°, preferably 9° orless). If the sheet a is folded along the folding ruled lines a2 to someextent, then the sheet a can be further folded as the respective workingtools 21-26 and 31-36 move and thereby be imparted complete directionalpermanency of folding.

2nd Embodiment of the Method of Imparting Directional Permanency ofFolding to a Sheet

The sheet used in this embodiment is a B type corrugated cardboard, inwhich many folding ruled lines a2 similar to that of the 1st embodimentare formed orthogonal to the corrugations al as shown in FIG. 18. Thesheet is longitudinally divided into a central part a9, in which thefolding ruled lines a2 have a longitudinal spacing w1 of 50 mm, andparts a8, on both sides of the part a9, in which the folding ruled linesa2 have a longitudinal spacing w of 100 mm.

The distances between the working tools 21-26 and 31-36 are adjusted tobe 100 mm by moving the working tools 21-26 and 31-36 somewhat to theright in the drawing by operating the upper and lower shuttle drivemeans 5, 5 a, 6, 6 a of the apparatus of FIG. 1.

Then the leading sheet part a8 is folded along the folding ruled linesa2 by operating the apparatus in the same manner as that of the 1stembodiment.

Next, when the sheet part a9 is to be folded, the distances between theworking tools 21-26 and 31-36 are adjusted to 50 mm by operating shuttledrive means 5, 5 a, 6, 6 a and the operation of the apparatus isrepeated as in the 1st embodiment.

When the posterior sheet part a8 is to be folded, the apparatus isoperated after adjusting the distances between the working tools 21-26and 31-36 in the above-mentioned manner.

The sheet a, to which directional permanency of folding is imparted asmentioned above, is folded in zigzag as shown in FIG. 19. That is, acorrugated cardboard block of an approximately square gutter shape isproduced by conveying the sheet a to the pasting process while extended(flat) and, after pasting, folding it by the folding device.

Otherwise, the method according to this embodiment is similar to that ofthe 1st embodiment.

3rd Embodiment of the Method of Imparting Directional Permanency ofFolding to a Sheet

The third embodiment of the method of imparting directional permanencyof folding to a sheet according to this invention will be explainedtogether with the operation of the apparatus of the above-mentionedembodiment with reference to FIGS. 1, 13 and 20-23.

The sheet a used in this embodiment is a B type corrugated cardboard, inwhich pairs of two folding ruled lines a2, a2 are formed in parallel atdistances w of 90 mm as shown in FIG. 13.

The folding ruled lines a2 have the same design as those of the firstembodiment and are formed approximately orthogonal to the corrugationsal. The distance w2 between folding ruled lines a2, a2 of the pair is 30mm.

By operating the shifting means 80, 81 and 9, and the shuttle drivemeans 5, 5 a, 6, 6 a of the apparatus of FIG. 1, the distances betweenthe tips of the lower working tools 21 and 22, 22 and 24, 25 and 26, andthe upper working tools 32 and 33, 34 and 35 are adjusted to be 30 mmand the distances between the tips of the working tools 31 and 21, 22and 32, 33 and 23, 24 and 34, 35 and 25, and 26 and 36 are adjusted tobe 90 mm.

After sheet a is supplied to the working position 1 b by the conveyingmeans 1 a, the tips of the respective working tools 21-26 and 31-36 areset to face the sheet a by operating the advancing drive means 7 a, 7 asshown in FIG. 20.

Then, the lower working tools 21-26 are gradually raised approximately80 mm by the folding drive means 4 and at the same time the respectiveworking tools 21-26 and 31-36 are moved rightward by the shuttle drivemeans 5, 5 a, 6, 6 a and the shifting means 80, 81 and 9. At that time,the vacuum chuck 1 g of the conveying means 1 a is controlled so as tomove in the same direction and at the same velocity as the last workingtool 36.

While the respective working tools 21-26 and 31-36 are moved in thismanner, the shifting means 9 is operated so as to keep the distancesbetween the respective pairs of working tools, 32 and 33, 34 and 35,constant while they are moved, by slowing the moving velocities of therespective working tools 31, 33, 35 by the shuttle drive means 6somewhat. The shifting means 80 is operated so as to keep the distancesbetween the respective pairs of working tools, 21 and 22, 23 and 24, and25 and 26 constant while they are moved, by increasing the movingvelocities of the respective working tools 21, 23, 25 by the shuttledrive means 5 somewhat.

By controlling the apparatus as mentioned above, ridge-like folds a6 andvalley-like folds a7 having an approximately U-shaped (or trapezoid) orreversed U-shaped sides are formed alternately among the pairs of thefolding ruled lines a2, a2, through the state shown in FIG. 21, to thestate shown in FIG. 22.

After the sheet a is folded as shown in FIG. 22, the respective workingtools 21-26 and 31-36 are retracted upward and downward, respectively,by the advancing drive means 7, 7 a. The part of the sheet, which hasbeen folded, is received by a pair of belt conveyers not shown in thedrawing. The folded sheet part received by the pair of belt conveyers isthen extended flat. When the processed sheet part is received by thepair of belt conveyers, the last part of the processed part of the sheetis held so as not to proceed by restricting means not shown in thedrawing.

Afterwards, the respective working tools 21-26 and 31-36 are returned totheir initial positions by the shuttle drive means 5, 5 a, 6, 6 a andthe apparatus is controlled to repeat the abovementioned processingcycle.

The sheet a, imparted with directional permanency of folding by themethod of the third embodiment, is conveyed to the pasting process inthe extended state and both sides of the folds are pasted. As the sheetis conveyed to the final molding station and processed there, a hollowcorrugated cardboard block of square shape as shown in FIG. 23 isproduced.

Since, otherwise the method of the second embodiment is similar to thatof the method of the first embodiment, explanation thereof is omitted.

4th Embodiment of the Method of Imparting Directional Permanency ofFolding to a Sheet

The 4th embodiment of the method of imparting directional permanency offolding to a sheet according to this invention will be explainedtogether with an operation of the apparatus with the reference to FIGS.1, 24 and 25.

The sheet a used in this embodiment is a B type corrugated cardboard andpairs of folding ruled lines a2, a2 separated by a distance w2 of 50 mmare formed on this sheet a, with spacings between pairs a2, a2,alternating between a distance w of 100 mm and a distance w3 of a littleless than 112 mm, as shown in FIG. 24.

The folding ruled lines a2, which have the same design as that of thefirst embodiment, are formed across the corrugations.

By operating the shifting means 80, 81 and 9 and the shuttle means 5, 5a, 6, 6 a, as shown in FIG. 25(e), the mutual distances between thelower working tools 21-26 and the mutual distances between the lowerworking tools 31-36 are in accord with those of the respective foldingruled lines a2 formed on the sheet a of FIG. 24.

The sheet a is supplied to the working position 1 b by the conveyingmeans 1 a and then the respective working tools 21-26 and 31-36 are setby the advancing drive means 7, 7 a to face the sheet a as shown in FIG.25(a).

Then, the lower working tools 21-26 are gradually raised byapproximately 90 mm and the respective working tools 21-26 and 31-36 aremoved rightward in the third embodiment.

By this operation, as shown in FIG. (b), the distances between therespective working tools 31 and 21, 33 and 23, 24 and 34, 35 and 25, 26and 36 are shortened in a uniform ratio, while the distances between theworking tools of the pairs, 21 and 22, 32 and 33, 23 and 24, 34 and 35,25 and 26, are kept constant.

By controlling the apparatus as mentioned above, ridge-like folds a6 andvalley-like folds a7 having somewhat deformed trapezoid or reversedtrapezoid sides are formed alternately along the respective pairs of thefolding ruled lines a2, a2 in the sheet a through the state shown inFIG. 25(a).

When the sheet a has been folded as mentioned above, the respectiveworking tools 21-26 and 31-36 are retracted upward or downward,respectively, by the advancing drive means 7, 7 a and the processed partof the sheet a is received by a pair of belt conveyers not shown in thedrawing.

Afterwards, the respective working tools 21-26 and 31-36 are returned totheir original positions by the shuttle drive 5, 5 a, 6, 6 a and theapparatus is controlled so as to repeat the abovementioned cycle.

The sheet a having directional permanency of folding imparted by themethod of the fourth embodiment is conveyed to the pasting process whileextended and, after both sides of the folds have been pasted, isconveyed to the final molding process. Then a corrugated cardboardhollow block of a square shape is manufactured as shown in FIG. 25(c).

Since the method of the fourth embodiment is otherwise similar to themethod of the third embodiment, explanation thereof is omitted.Advantages of the Apparatus of the First Embodiment In the apparatus forimparting directional permanency to a sheet according to the firstembodiment, the sheet a can be imparted directional permanency offolding so as to be folded in zigzag along the folding ruled lines a2 ofthe sheet a accurately, since the apparatus is provided with the foldingworking tools 21-26 and the folding working tools 31-36, the lowerworking tools 21-26 are shifted by the folding drive means 4 so thatthey are advanced to the opposite side of the sheet a and, concurrentlywith the shift, the respective folding working tools 21-26 and 31-36 arecontrolled to be moved in the same direction by the shuttle drive means5, 5 a, 6, 6 a so that the distances therebetween are shortened in auniform ratio.

In the apparatus according to the first embodiment, the processed sheeta can be smoothly conveyed to further processing, since the advancingdrive means 7, 7 a move the respective working tools 21-26 and 31-36away from or toward the sheet a.

In addition, by providing the above advancing drive means 7, 7 a, thecontrol cycle of imparting directional permanency of folding to thesheet a can be repeated.

In the apparatus of the first embodiment, the shifting means 80, 81 and9 shift the respective folding working tools 21-26 and 31, 33, 35, toproperly adjust their relative positions and the moving velocity of therespective working tools 21-26, 31, 33, 35 can be adjusted by theshuttle drive means 5, 5 a, 6.

Accordingly, directional permanency of folding can be imparted to thesheet a by a single apparatus so that the sheet is folded in zigzag andso that ridge-like (reversed U-shaped) folds and valley-like (U-shaped)folds are formed alternately in the sheet a.

In addition, the moving velocity of the respective working tools 21-26and 31-36 can be corrected very easily and controlled more accurately,since the shifting means 80, 81 and 9 are respectively composed of therespective screw shafts 80 h, 81 h and 9 b for each of which the numberof rotations is properly controlled by the respective motors 80 g, 81 gand 9 a, and the screw guides 80 i, 81 i and 9 c through which theshafts penetrate, etc.

According to the apparatus of the first embodiment, when some of theworking tools are not required for imparting directional permanency tothe sheet a (some of the working tools 21-26 may be unnecessarydepending on the distance between the folding lines a2 of the sheet a ina given design, these working tools can be retracted independently,since the respective folding working tools 21-26 on one side of theworking position are respectively provided with actuators 21 a-26 a formoving them independently toward or away from the sheet a.

The apparatus is simple, since the actuators 21 a-26 a also function asthe advancing drive means 7 a.

The apparatus of the first embodiment is very advantageous for repeatingthe cycle of imparting directional permanency of folding and conveyingof the sheet a, since it is provided with the conveying means 1 a forsupplying the sheet a to the working position 1 b by conveying itlongitudinally and the shuttle drive means 5, 5 a, 6, 6 a move therespective folding working tools in the direction of conveyance by theconveying means.

According to the apparatus of the first embodiment, the sheet a can besupplied to the working position 1 b in a stable state and directionalpermanency of folding of the sheet a can be performed smoothly, sincethe apparatus is provided with, at the working position 1 b of the sheeta, the sheet guides 1 h, which consist of many guide bars 1 i, aredisposed in parallel and along the longitudinal direction of the sheetand with, corresponding to the guide bars 1 i, many indentations 20provided on the tip parts of the folding working tools 21-26 shifted bythe folding drive means 4.

According to the first embodiment, operations of the respective workingtools can be controlled easily, since the sheet a is suppliedhorizontally to the working position, the respective folding workingtools 21-26 facing one side of the sheet a are disposed so as to facethe sheet from underneath and the respective folding working tools 31-36facing the other side of the sheet a are disposed so as to face thesheet from above.

The respective working tools 21-26 and 31-36 can be controlled veryeasily so that the initial distances between them are shortened in auniform ratio, since the shuttle drive means 5, 5 a, 6, 6 a are providedwith the respective sprockets corresponding to the folding working tools21-26 and 31-36 and with timing belts respectively mounted on thesprockets. Because the sprocket corresponding to the respective foldingworking tools 21-26 facing the one side of the sheet a and the sprocketcorresponding to the respective folding working tools 31-36 facing theother side of the sheet a are driven by different motors thecircumferential velocities of the respective timing belts can bedifferent.

Also in the first embodiment, since the main parts of the foldingworking tools 21-26 and 31-36 are connected to the base partsexchangeably, the main parts can be exchanged easily.

In addition, since the base parts of the folding working tools 21-26 and31-36 are plates, it is easy to impart the abovementioned directionalpermanency of folding to the sheet a. The Apparatus of the SecondEmbodiment The second embodiment has working tools 21-26 with a T-shapedsection as shown in FIG. 26(a), with a L-shaped section as shown in FIG.26(b), with a U or Y-shaped section as shown in FIG. 26(c) and with athickness the same as the distance between the ruled lines pair a2, a2as shown in FIG. 26(d) respectively.

When the method of the third embodiment or the fourth embodiment iscarried out using the apparatus of the second embodiment, the amount ofshifting of the working tools can be made smaller by using foldingworking tools 21-26 and 31-36, having cross-sections as shown in FIGS.26(a)-26(d).

The Other Embodiments

Although only the lower folding tools 21-26 are moved in the directionof the sheet a by the folding drive means 4 in the apparatus of theabove embodiments, both the upper and lower working tools may be movedin the folding direction of the sheet a simultaneously. Alternatively,only the upper folding working tools may be moved in the foldingdirection of the sheet a.

Although corrugated cardboard is described as the sheet a in the methodof above-mentioned embodiments, an ordinary pasteboard can be used forthe sheet a. When the sheet a is pasteboard, the folding ruled lines a2may be pressed lines formed by pressing the corresponding portion of thesheet a linearly or may be intermittent cut lines such as perforatedlines.

The sheet a may be cut out to a suitable flat shape according to thedesign of the product and, if required, indentations (cut outs) or holes(openings) may be formed in the sheet a.

Further, the sheet a may be synthetic paper or other material as long asit has a thickness of some extent and is capable of being folded.

By using the apparatus of the first embodiment, disposing the respectivefolding working tools 21-26 and 31-36 as shown in FIG. 14(b), impartingdirectional permanency of folding to the sheet a, disposing therespective folding working tools 21-26 and 31-36 as shown in FIG. 20 orFIG. 25(e) and imparting directional permanency of folding to the sheeta, directional permanency of folding can be imparted to the sheet a suchthat the folds as shown in FIG. 14(b) and the folds as shown in FIG. 20or FIG. 25(e) are formed in combination.

The shuttle drive means for moving the respective folding working tools21-26 and 31-36 during working while shortening their initial distancesin a uniform ratio, the shifting means for shifting the working tools21-26 and 31-36, and the advancing drive means for moving the workingtools 21-26 and 31-36 away from the sheet a as required may be providedseparately for the respective folding working tools 21-26 and 31-36. Inthis manner, the mutual distances intervening between the respectiveworking tools 21-26 and 31-36 can be set and adjusted more freely. Andwhen directional permanency of ridge-like folding and directionalpermanency of valley-like folding are imparted to the sheet aalternately, even if the distance between the folding ruled lines or thedistance between the folding ruled lines of the pair differs in the samesheet a, the directional permanency of folding can be accuratelyimparted along the folding ruled lines a2 or the pairs of the foldingruled lines a2, a2.

In addition, in the above-mentioned constitution, directional permanencyof folding can be imparted to a sheet by arbitrarily selecting a singleworking tool or a single pair of the working tools among the respectivefolding working tools 21-26 and 31-36 as a reference and moving theother working tools toward the working tool or the pair of working toolsselected as the reference, while the shuttle drive means for the workingtool(s) of the reference is not operated.

The method of imparting directional permanency of folding to a sheet andthe apparatus therefor according to the present invention are useful formanufacturing a block product, such as frames for packaging andcushioning members, from a sheet of paper or other easily recyclablematerials.

What is claimed is:
 1. A method of imparting directional permanency offolding to a sheet, having parallel opposing edges extending along alongitudinal dimension of the sheet and a plurality of pairs of parallelruled folding lines which are orthogonal to the longitudinal dimension,by forming ridge-like and valley-like folds in the sheet, said methodcomprising the steps of: a first step of conveying the sheet along alinear path extending to and including a planar working position; asecond step of disposing pairs of folding working tools in initialpositions aligned with corresponding pairs of the respective ruledfolding lines on a surface of the sheet which becomes an inner surfacewhen the sheet is folded along the respective ruled folding lines; athird step of moving said pairs of folding working tools perpendicularto the planar working position to engage and fold the sheet along therespective pairs of the ruled folding lines; a fourth step of shiftingthe folding working tools engaging the sheet, parallel to the linearpath, to shorten distances between the respective pairs of the foldingworking tools in accordance with a ratio based on an apparent amount ofshortening of the longitudinal dimension caused by the shifting, insynchronization with the third step; a fifth step of retracting therespective pairs of the folding working tools from the sheet after thefourth step; a sixth step of returning the respective pairs of thefolding working tools to their initial positions; and repeating thefirst through the sixth steps; and wherein the sheet is a corrugatedcardboard, and at least some of the ruled lines are intermittent cuttinglines formed by cutting the sheet intermittently across corrugations andare each composed of cuts of a predetermined length formed in the sheetand non-cut portions of a shorter length than the predetermined length,said cuts and non-cut portions alternating across one dimension of thecorrugated cardboard, transverse to the corrugations, and, extendingobliquely from each end of each cut, an additional cut of a shorterlength then said predetermined length.
 2. A method of impartingdirectional permanency of folding to a sheet, having parallel opposingedges extending along a longitudinal dimension of the sheet and aplurality of pairs of parallel ruled folding lines which are orthogonalto the longitudinal dimension, by forming ridge-like and valley-likefolds in the sheet, said method comprising the steps of: a first step ofconveying the sheet along a linear path extending to and including aplanar working position; a second step of disposing pairs of foldingworking tools in initial positions aligned with corresponding pairs ofthe respective ruled folding lines on a surface of the sheet whichbecomes an inner surface when the sheet is folded along the respectiveruled folding lines; a third step of moving said pairs of foldingworking tools perpendicular to the planar working position to engage andfold the sheet along the respective pairs of the ruled folding lines; afourth step of shifting the folding working tools engaging the sheet,parallel to the linear path, to shorten distances between the respectivepairs of the folding working tools in accordance with a ratio based onan apparent amount of shortening of the longitudinal dimension caused bythe shifting, in synchronization with the third step; a fifth step ofretracting the respective pairs of the folding working tools from thesheet after the fourth step; a sixth step of returning the respectivepairs of the folding working tools to their initial positions; andrepeating the first through the sixth steps; and wherein the sheet is apasteboard, and at least some of the ruled lines are one of pressedlines formed in the sheet by a press and intermittent cutting linesformed in the sheet by cutting.
 3. An apparatus for impartingdirectional permanency of folding to a sheet having parallel opposingedges extending along a longitudinal dimension of the sheet, and aplurality of parallel ruled folding lines which are orthogonal to thelongitudinal dimension; a plurality of folding working tools which, in astandby position, are spaced a predetermined distance apart along thelongitudinal dimension of the sheet and are alternately positioned onopposing sides of a planar working position for receiving the sheet,said folding working tools having distal edges which, in initialpositions, are in alignment with the ruled folding lines when the sheetis received at the working position, each of said folding working toolsincluding a base portion and a main portion with one of said distaledges, said main portions being exchangeably connected to said baseportions; advancing drive means for moving a first plurality of saidworking tools perpendicular to the planar working position between aposition adjacent the sheet and a retracted position; folding drivemeans for moving a second plurality of said folding working toolsperpendicular to the sheet to bend the sheet to some extent along therespective ruled folding lines and for returning the working tools bymovement away from the sheet; and shuttle drive means for moving atleast one of said pluralities of folding working tools parallel to theplanar working position and relative to each other in accordance with auniform ratio and for returning the working tools to their initialpositions.
 4. The apparatus for imparting directional permanency to asheet according to claim 3 further comprising: conveying means fortransporting the sheet to the working position through a path defining aconveyance direction; and wherein the shuttle drive means move therespective folding working tools in the conveyance direction.
 5. Theapparatus for imparting directional permanency to a sheet according toclaim 3 further comprising: a plurality of guide bars arranged in aparallel array extending along the direction of the longitudinaldimension of the sheet at the working position, wherein said distaledges of said folding working tools have grooves corresponding to theguide bars.
 6. The apparatus for imparting directional permanency to asheet according to claim 3, wherein the sheet is conveyed to the workingposition horizontally and one plurality of the folding working tools isarranged below the working position, facing one side of the sheet, and asecond plurality of working tools is arranged above the workingposition, facing the other side of the sheet.
 7. The apparatus forimparting directional permanency to a sheet according to claim 3,wherein said shuttle drive means comprises at least first and secondshuttle drives respectively located on opposite sides of said workingposition; wherein each of said shuttle drives comprises: at least onepair of sprockets; endless drive bands mounted around the one pair ofsprockets and supporting a plurality of said folding working tools;pairs of guide rails which guide movement of the respective foldingworking tools; and a motor for driving one of said sprockets; andwherein the motors of said first and second shuttle drives areseparately operable to allow the endless drive bands of said firstshuttle drive to be driven at different speeds than the endless drivebands of said second shuttle drive.
 8. The apparatus for impartingdirectional permanency to a sheet according to claim 3, wherein the mainportions of the folding working tools are plates.
 9. The apparatus ofimparting directional permanency to a sheet according to claim 3 furthercomprising actuators for independently moving at least some of thefolding working tools toward and away from the planar working position.10. An apparatus for imparting directional permanency of folding to asheet having parallel opposing edges extending along a longitudinaldimension of the sheet, and a plurality of parallel ruled folding lineswhich are orthogonal to the longitudinal dimension; a plurality offolding working tools which, in a standby position, are spaced apredetermined distance apart along the longitudinal dimension of thesheet and are alternately positioned on opposing sides of a planarworking position for receiving the sheet, said folding working toolshaving distal edges which, in initial positions, are in alignment withthe ruled folding lines when the sheet is received at the workingposition, each of said folding working tools including a base portionand a main portion with one of said distal edges, said main portionsbeing exchangeably connected to said base portions; advancing drivemeans for moving a first plurality of said working tools perpendicularto the planar working position between a position adjacent the sheet anda retracted position; folding drive means for moving a second pluralityof said folding working tools perpendicular to the sheet to bend thesheet to some extent along the respective ruled folding lines and forreturning the working tools by movement away from the sheet; and shuttledrive means for moving at least one of said pluralities of foldingworking tools parallel to the planar working position and relative toeach other in accordance with a uniform ratio and for returning theworking tools to their initial positions; and shifting means forshifting the other plurality of the folding working tools to shorten orelongate the distances between adjacent working tools.
 11. The apparatusfor imparting directional permanency to a sheet according to claim 10,wherein said shifting means include screw shafts, screw guides throughwhich said screw shafts extend, and motors for rotatably driving saidscrew shafts.
 12. A method of imparting directional permanency offolding to a sheet, having parallel opposing edges extending along alongitudinal dimension of the sheet and a plurality of parallel ruledfolding lines which are orthogonal to the longitudinal dimension, byforming ridge-like and valley-like folds in the sheet, said methodcomprising: a first step of conveying the sheet along a linear path toand including a planar working position defined by a support surface; asecond step of disposing working tools in initial positions with each ofthe working tools aligned with a different one of respective ruledfolding lines, on at least one surface of the sheet, the working toolsin the initial positions being arranged, with spacings therebetween, ina linear array extending parallel to the linear path and coextensivewith the planar working position, with one working tool located at oneend of the array designated as a reference working tool; a third step ofbringing the working tools into engagement with the respectively alignedruled folding lines and shifting at least a first plurality of theworking tools, parallel to the linear path, in one direction, forfolding the sheet along the respective ruled folding lines; and a fourthstep of moving the working tools other than the reference tool, whileengaging the sheet, toward the reference working tool, to shorten thespacings between working tools, in accordance with a ratio based on anapparent amount of shortening of the longitudinal dimension caused bythe shifting, in synchronization with the third step; and wherein thesheet is a corrugated cardboard, and at least some of the ruled linesare intermittent cutting lines formed by cutting the sheetintermittently across corrugations and are each composed of cuts of apredetermined length formed in the sheet and non-cut portions of ashorter length than the predetermined length, said cut and non-cutportions alternating across one dimension of the corrugated cardboard,transverse to the corrugations, and, extending obliquely from each endof each cut, an additional cut of a shorter length then saidpredetermined length.
 13. A method of imparting directional permanencyof folding to a sheet, having parallel opposing edges extending along alongitudinal dimension of the sheet and a plurality of parallel ruledfolding lines which are orthogonal to the longitudinal dimension, byforming ridge-like and valley-like folds in the sheet, said methodcomprising: a first step of conveying the sheet along a linear path toand including a planar working position defined by a support surface; asecond step of disposing working tools in initial positions with each ofthe working tools aligned with a different one of respective ruledfolding lines, on at least one surface of the sheet, the working toolsin the initial positions being arranged, with spacings therebetween, ina linear array extending parallel to the linear path and coextensivewith the planar working position, with one working tool located at oneend of the array designated as a reference working tool; a third step ofbringing the working tools into engagement with the respectively alignedruled folding lines and shifting at least a first plurality of theworking tools, parallel to the linear path, in one direction, forfolding the sheet along the respective ruled folding lines; and a fourthstep of moving the working tools other than the reference tool, whileengaging the sheet, toward the reference working tool, to shorten thespacings between working tools, in accordance with a ratio based on anapparent amount of shortening of the longitudinal dimension caused bythe shifting, in synchronization with the third step; and wherein thesheet is a pasteboard, and at least some of the ruled lines are one ofpressed lines formed in the sheet by a press and intermittent cuttinglines formed in the sheet by cutting.